One Owner, Three Entities, One Stack: A Case Study in Shared Digital Infrastructure Across Indonesian PTs

This paper examines the operational reality of running three separate Indonesian limited liability companies (Perseroan Terbatas) on a single shared digital infrastructure stack. Drawing from the author's direct experience managing entities across industrial services, engineering consultancy, and craft manufacturing, the study documents the specific tools, costs, and workflow patterns that emerge when a sole owner consolidates digital operations rather than maintaining separate systems per entity. The shared stack comprises Google Workspace, shared drives, WhatsApp-based coordination, CRM, digital attendance systems, and unified marketplace and e-procurement listings. With 25 employees across three entities and a monthly digital infrastructure cost of approximately $156, the case demonstrates that infrastructure consolidation is technically straightforward and economically rational. However, the study identifies a less-discussed bottleneck: the cognitive load of context-switching between entities. The paper proposes a Digital Entity Infrastructure Maturity Model (DEIMM) and positions the case study at Stage 4 (Shared Stack), arguing that most Indonesian multi-entity MSMEs operate at Stage 1 or 2 without recognizing it.